As a device adapted to output light in response to the input of sound, a sound detector is disclosed in, for example, Japanese Laid-open Patent Publication No. 6-241882. This sound detector includes a microphone for converting input sound into an electrical signal and an amplifier circuit for amplifying the electrical signal. The voltage of the amplified signal is compared with a predetermined reference voltage, and if the signal voltage is higher than the reference voltage, a light emitting diode is lighted. Various applications of the sound detector may be envisaged. For example, the sound detector is attached to a sound source, and light emission from the sound detector is visually observed to find generation timings of sounds. Moreover, the sound detector may be attached to each of a plurality of sound sources. In that case, visual observation of light emission from sound detectors makes it possible to find that sound source from which sound is output.
However, in such an arrangement, since the sound detector disclosed in Japanese Laid-open Patent Publication No. 6-241882 is simply lightened in response to the input of sound, it is only possible to visually confirm whether or not sound generation takes place. Thus, it has been demanded to develop an apparatus which has a variety of forms of use and response.
In consideration of the above circumstances, an object of the present invention is to provide a light-emission responder responding to the input of sound, which is capable of realizing various forms of response and being usable in various forms of use.